Siemens Showcasing Voice over WLAN (VoWLAN) for Office and Industrial use



Voice and data networks are converging. Even if they happen to be wireless. At this year's CeBIT, Siemens is showcasing a voice over WLAN solution (VoWLAN) that is geared for office and industrial environments.

-/14 March, 2005 - Wi-Fi Technology News/- If someone takes a WLAN device from one part of a conventional WLAN network to another or, within a building, from one access point (AP) to another, the connection has to be literally "handed over". For this to happen, a new IP address has to be allocated and the device has to sign on to the network again.

The problem is that that delays transmission. "When you are transferring data, latency at the handover point doesn't really matter," says Dirk Abel of Technical Sales at Siemens. "But in a voice network, any delay of over 15 ms causes annoyance. Words are truncated. It becomes difficult to follow a phone conversation."


Second-generation WLANs from Siemens drive latency at handover down below the critical threshold. How does this work? The smart innovation is not at the "fat access point", which is blissfully unaware of all the adjacent APs, but in the central HiPath WLAN controller, which manages up to 200 "fit APs". As a result, the device is assigned an IP address that remains unchanged at the handover between APs.

Nor is that the only benefit of a centralized network architecture. Should one AP go down, the controller compensates by ramping up transmission via adjacent APs. A new AP can then simply be plugged in and the problem is solved. Multiple controllers can work together in a networked configuration too, allowing them to manage very large networks. At the same time, the traffic load is balanced out between controllers to optimize throughput speed. Again, if one controller fails, the others do its work for it. "All of which adds up to a dynamic but robust network," Abel notes.

At CeBIT, Siemens is demonstrating not just APs designed for office environments, but also the more rugged versions intended for industrial settings ? all from a single source. "That is what sets Siemens apart in the eyes of our customers," Abel continues. The finishing touch to Siemens' WLAN portfolio is provided by a new WLAN phone, the optiPoint WL2 professional, whose design and menu guidance are very close to the look and feel of the Gigaset series.

For further information please click here http://www.siemens.com/hipath.